Caption: Light microscopy of two renal corpuscles in the kidney. Entering and exiting the corpuscle at one pole are arterioles which form a compact branched mass of capillary loops with red blood cells inside them. These capillaries, known as a glomerulus, provide for a selective filter of blood plasma that circulates through them, constituting the primary mechanism by which the kidney removes waste products from the blood stream that later results in urine production. This initial filtrate also called provisional urine, passes into the gap (Bowman's space) between the glomerulus and the margin of the corpuscle called Bowman's capsule. There may be a million renal corpuscles in each adult human kidney, all of which are developed before birth there being no further increase in postnatal life. The surrounding renal tubules make up the passageways of the nephrons through which further modification of the filtrate occurs prior to its discharge into the ureter and then the urinary bladder. Magnification x180 when printed at 10 cm.